The comparison to Netflix is ridiculous. Netflix being awesome is not a function of centralized being better than decentralized, it's a function of torrented content being illegal 99/100 times and thus it's very tricky to commercialize it, apart from (shady) ad networks that accept the mere indexing of torrent links.
But consider for a moment the popularity of Popcorn time or torrents in general. They're massively popular despite the fact everyone knows it's illegal and knows many countries have histories of punishing illegal downloaders, let alone the big uploaders. And it's not just that they're popular, they work really, really well for something completely free.
Does that mean we prefer using commercial solutions most of the time? It depends. Torrenting tech is monetized through ads but kept free, just like things like gmail or facebook. The difference is that gmail isn't illegal and thus can get venture capital investments, partnerships, build elaborate products (like gmail for business) that interface with online identities (like businesses, phone security) and infrastructures (banking & payment processing infrastructure), have customer service etc. While most torrenting services have to operate in the dark, anonymously, outside of infrastructure, with few partnerships, little investment etc.
In short, I don't think we should try to reason from analogy here. Centralized/decentralized doesn't inherently predict anything.
I think at the end of the day we have to look at the 'per person' scale. The average US citizen makes 2 transactions a day (one of the metrics I saw used in this slideshow, too.) The average bitcoin transaction is 500 bytes. For a global citizen it's likely slightly less than 2 on average considering the US one of the most consumerist societies, but let's say 2 for everyone.
Alright so 1 kilobyte of data per day for everyone in the world.
Is that a big deal? No. It's not. It's still 14 TB of data, daily, but it's manageable.
It requires an 82 mb/s connection to handle that much data. That's for the entire world populations (1 month old babies included!) to average as many transactions as the average US citizen.
Just put that into perspective. We're not talking about this kind of technology today, bitcoin has only a few million users. It's unlikely bitcoin will ever become popular enough to service 7 billion people in the first place, the internet's been around for decades and it's not even close, hell electricity or clean water doesn't even do that. But hypothetically if it happened, we'd be talking about some date that's at LEAST 20 years out from now to get to 7 billion and that in itself is already extremely optimistic. For perspective, it took the internet nearly 2 decades to get to 2 billion internet users.
So to say a 82 mb/s internet connection in 2035 is too big of a deal for what is likely going to be a node run by a professional business like Coinbase. (i.e. I believe bitcoin's infrastructure will be run more and more by professional businesses rather than home desktop PCs, but these businesses will exist in every country on the planet and be decentralized a bit like how ISPs are decentralized only much more because running a node isn't nearly as big a deal obviously, as it's one of many things running on the ISP's network).
Average home internet is about 5 megabytes per second today in OECD countries. And we know bandwidth, like CPU and storage, has grown roughly 50-60% in the past decades and it's likely to average something close to that (like 40-50%) in the next few decades. 50% yoy would be 3300x in 20 years. 5 MB/S would be 15 gb/s by 2035. Optimistic? Absolutely, it's the most optimistic metric based on past data. But let's just say it's extremely likely that reaching 1 gigabyte per second will easily happen by the time a bitcoin node needs 0.082 gigabytes per second. And that's for a standard, average, consumer, home connection. NOT the much better industrial connections that you expect bitcoin nodes will be hooked into by 2035 (if it indeed is so important that 7 billion people use it for 2 transactions a day).
In short, 1 kilobyte of data per person is so little that whether it's centralized or decentralized it doesn't really matter that much. It can be dealt with. Especially when you consider that many of these transactions can happen off-chain, on sidechains, treechains, less secure chains (e.g. to buy coffee or make a 1 cent payment to read a New York Times article automatically instead of being served a 10 second advertisement with a 1 cent revenue per view value, these transactions can happen on less secure channels).
Decentralized/centralized is an interesting discussion, sure, but at the 1 kilobyte per day per person scale, I don't think it's very relevant when it comes to technical scalability. It's relevant for other reasons definitely (like a decentralized digital global banking system being much less prone to anti-competitive banking monopolies and licensing than say a centralized one like Paypal) but I don't think technical scalability is the biggest problem.
Beyond that bitcoin is so nascent and small... I mean I quite like it and think it just might win, but I still feel it's a bit silly to talk about whether bitcoin can scale to a billion users all the time, when its growth rates are really not all that impressive. I mean don't get me wrong, scalability is important to talk about, but it commands such a disproportionate amount of talk. It's like wondering if 50% of the Mars debate was about whether Mars can support a city of a million humans, let's see if we can get 20 people living there first you know?